i use to have a TBS on my last ride. It was an Airaid TBS. It had a crazy ringed design that looked like the outside of a top of a bottle. supposedly it swirled the air around to burn more efficiently. It made a cool hissing sound. Its a trick lil mod that will make your intake noise stand out but other than that I dont think it does anything. Never noticed any mpg increase although Airaid said you might.